1. Field of the Invention
The present invention relates to an agricultural machine comprising a carrier vehicle and several working units intended to cut standing plants, said working units being connected to said carrier vehicle.
2. Discussion of the Background
A self-propelled mower comprising a carrier vehicle and three working units so as to cover a wide cutting area and improve the productivity of the machine exists in the prior art. More specifically, this mower comprises a frontal working unit and two lateral working units. This mower has a working width that can be as much as somewhat over 9 meters. In order to move it around on the roads, it has been necessary to provide a smaller-width transport position in which the lateral working units are pivoted vertically.
In order to increase the working width still further and thus improve cutting performance, a greater number of working units has been envisaged. Patent FR 2 837 347 in particular anticipates the possibility of using at least two frontal working units situated in the direction of forward travel of the carrier vehicle in front of the latter, and at least two lateral working units. A transport position is anticipated for each working unit and more specifically a substantially vertical folding position for the two lateral working units.
A carrier vehicle such as this comprising three frontal working units and two lateral working units has recently been marketed. The lateral working units of this agricultural machine are articulated on the sides and in the middle of the carrier vehicle and are deployed using telescopic arms.
The lateral working units in the known prior art are perpendicular to the length of the carrier vehicle and situated between the groups of tires, namely substantially in the middle of the vehicle, or at the rear of said vehicle. This configuration of the lateral working units has the drawback that the driver of the carrier vehicle cannot readily and constantly see all the working units and anticipate unevennesses of the ground or obstacles by raising said working units, when turning to avoid said obstacles or alternatively when adapting the speed of said vehicle. Said arrangement of the lateral working units also presents a major drawback when driving the agricultural machine around bends.
In fact, in this configuration of use, the working units no longer offer a recut zone, that is to say an overlapping zone of the working units, and uncut strips of land therefore remain, these strips increasing in width with the tightness of the curve through which the agricultural machine is driven. In order to palliate this problem, the recut zones may be increased when the agricultural machine is negotiating a bend, but that leads to a higher overall cost of agricultural machine with a solution that is not entirely satisfactory.
As rotary movements and curves of the carrier vehicle in the fields are extremely frequent, this problem of completely cutting the plants is, for many farmers, important to solve.
In the agricultural machines already described and in the context of the present invention, the working units arranged around the carrier vehicle may be plant-cutting elements alone or cutting elements associated with devices for conditioning the forage, and therefore agricultural machines categorized as mowers or as mower-conditioners. Such agricultural machines may also comprise wide-spreading devices or devices for grouping cut plants into windrows, to make it easier to pick them up later using a silo loader for example.
In order to cut the widest possible working area, the working units have increasingly long lengths. Folding said working units about the carrier vehicle in the transport position so as to comply with the maximum authorized dimension for travel on the public highway leads to a serious problem regarding visibility from the cab of said carrier vehicle for driving and to great difficulties in positioning the working units around the carrier vehicle.
A problem therefore arises that is connected both with the positioning of the working units as functionally as possible during work, particularly in the case of large-sized working units, and a difficulty connected with the transport configuration which needs to allow the agricultural machine to be driven easily on the public highway.